2005 B&B Electronics. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photography, recording, or any information storage and retrieval system without written consent. Information
in this manual is subject to change without notice, and does not represent a commitment on the part of B&B Electronics.
B&B Electronics shall not be liable for incidental or consequential damages resulting from the furnishing, performance, or use of
this manual.
All brand names used in this manual are the registered trademarks of their respective owners. The use of trademarks or other
designations in this publication is for reference purposes only and does not constitute an endorsement by the trademark holder.
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com
Thank you for purchasing an ES1AWB Wireless Serial Server. Like all
B&B Electronics products, your serial server has been manufactured to high
standards of quality and performance to ensure your complete satisfaction.
Please read this manual and carefully follow the instructions to achieve best
results. For additional information on this and other products and for
technical support, contact B&B Electronics.
About Your ES1AWB Wireless Serial Server
ES1AWB Wireless Serial Servers are part of B&B Electronics’ growing
family of device servers, products that allow you to connect equipment with
available serial connections into existing networks. ES1AWB wireless serial
servers connect RS-232 devices to a wireless network via wireless access
points, eliminating the need for network cabling. Based on the 802.11b
wireless standard, ES1AWB servers operate at up to 11 Mbps over the 2.4
GHz band, which does not require licensing.
A serial device connected to the serial port on your ES1AWB can be
accessed from any node on the LAN using virtual COM port, console
management, TCP and UDP socket, serial bridge, modem emulation and
custom connections. Network addresses can be obtained dynamically or
manually. Simple Network Management Protocol (SNMP) is supported.
Configuration is accomplished through a web-based user interface.
Features
•Wireless networking at up to 11 Mbps on the 2.4 GHz band, as
specified by the 802.11b standard
• Serial port supports RS-232 using a standard DB-M connector
• Software Support - Windows 98/ME/ 2 0 00/XP/NT 4.0 or Vista
• Firmware upload for future revisions/upgrades
• Small compact case
• LEDs indicate link integrity and data transfer activity
• Web Configuration and Management user interface
• Email event notification
Communication Modes
ES1AWB Wireless Serial Servers allow you to connect serial devices over
a wireless network. The connection can be configured in several modes.
Direct IP
Direct IP Mode allows applications using TCP/IP or UDP/IP socket
programs to communicate with the asynchronous serial ports on the serial
server. In this mode the ES1AWB is configured as a TCP or UDP server. The
socket program running on the PC establishes a communication connection.
The data is sent directly to and from the serial port on the server.
•TCP Server Mode allows network devices to initiate a TCP connection
to the serial device connected to the serial port on the ES1AWB. This is
also referred to as reverse telnet.
•UDP Server Mode allows network devices to initiate a UDP connection
to the serial device attached to the serial port of the ES1AWB. When
using UDP protocol the ES1AWB can be configured to broadcast data to
and receive data from multiple IP addresses.
Virtual COM Port
Virtual COM Port mode (also called COM port redirection) allows you to
map a COM port on your PC to the serial port on your ES1AWB. Using the
RealPort software (included with the ES1AWB) you create virtual COM
ports on your PC. When your application sends data to this port, RealPort
redirects the data across the network to serial device connected to the
ES1AWB serial port. The network is transparent to the user application and
the serial device connected to the ES1AWB.
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com
Paired Mode (also called Serial Tunneling or Serial Bridge mode) allows
serial devices connected to two ES1AWB serial servers to communicate
across a network. The two ES1AWB serial servers automatically connect to
each other.
In Paired Mode the heartbeat feature ensures reliable communications by
restoring the connection if communications are temporarily lost at either end
due to loss of power or Ethernet connection.
Other Communications Modes
ES1AWB Wireless Serial Servers also feature the following communications
profiles:
Modem Emulation Mode allows you to configure the serial port to operate
as if it is a modem. For legacy applications where a serial device is set up to
communicate through a modem, the serial device can now be connected to
the ES1AWB and communication occurs over the network. The ES1AWB
emulates modem responses to and from the serial device.
In Console Management Mode the ES1AWB can be configured for
connection to the management port typically found on network devices such
as routers, switches and servers. This allows remote management of the
network device. Communication can be accomplished using telnet to a
specific port in the serial server.
Custom Mode allows you to custom configure the ES1AWB serial port and
is used if your application does not fit into any other predefined modes.
802.11 Wireless Networking Basics
ES1AWB wireless serial servers allow you to connect non-network-enabled
serial devices into a wireless network, giving you the capability to gather
more data and implement remote programming and management. Serial
devices no longer are limited to a physical connection to a PC. The serial
device can be connected to an ES1AWB wireless serial server anywhere
within range of an 802.11b-compatible wireless access point.
Communication occurs transparently using TCP/IP or UDP/IP over a
wireless link. This allows traditional Windows PC software access to serial
devices anywhere on the wireless network.
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com
The enabling technology for ES1AWB wireless serial servers is based on the
IEEE 802 standard. Some background on the standard follows.
802.11 Wireless Networking
IEEE 802.11 is a set of standards that defines how multiple devices can
communicate on a wireless network. The standard has grown into a set of
several standards that define various features and functions. The 802.11b
standard defines the physical and data link layers for a wireless network
using the 2.4 GHz frequency band, a band that does not require licensing. As
a part of the IEEE family of standards, 802.11 WLANs are easily connected
to 802.3 (Ethernet) LANs. Higher layer LAN protocols, network operating
systems and internetworking protocols such as TCP/IP integrate seamlessly.
Under the IEEE 802.11 standard there can be two different types of devices
on the wireless network: stations and access points (AP). A station may be a
PC equipped with a wireless network adapter or it can be a wireless serial
server such as the ES1AWB. An 802.11 access point is a radio with an
interface that allows connection to a wired LAN. Access points run bridging
software to facilitate the connection from wireless to wired network. The
access point becomes the base station for the WLAN. It aggregates access to
the wired network for multiple wireless stations. An access point may be a
standalone device, such as a wireless router or switch, or a card in a PC.
Wireless Network Configurations
The 802.11 standard defines two modes of operation: infrastructure mode
and ad hoc mode. Infrastructure mode makes use of one or more access
points connected to a wired LAN. Wireless stations communicate with access
points to gain access to each other and/or the LAN. In the Basic Service Set
(BSS) several stations communicate with one access point, which is
connected to a wired LAN. In the Extended Service Set (ESS) two or more
access points connect to the LAN creating a sub network.
In ad hoc mode, also called Independent Basic Service Set (IBSS), access
points are not used. Wireless stations communicate directly with each other
in a peer-to-peer fashion. This mode allows individual computers to set up a
network where wireless infrastructure does not exist.
ES1AWB wireless serial servers can be configured to operate in
infrastructure or ad hoc mode. From the Web Configuration and
Management Interface you can set up the type of network, naming the
network (specifying the SSID, or service set identifier) and other parameters.
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com
IEEE 802.11b standard specifies a WLAN that operates on the 2.4 GHz band
at data rates up to 11 Mbps. Equipment that conforms to the 802.11b
standard can interoperate with equipment conforming to faster (up to 54
Mbps) 802.11g equipment and they will interoperate. However, when
connected into the same network the 802.11g equipment will operate at the
11 Mbps limitation of the 802.11b equipment.
For media access, 802.11 wireless networks use CSMA/CA, a scheme in
which a station that intends to transmit ‘listens’ for traffic on the radio carrier
frequency and sends data packets if the frequency is clear. If the receiving
station receives the packet intact it sends an acknowledgement (ACK) to
confirm the packet has been received. If the transmitting station does not
receive an ACK it assumes a collision occurred and transmits again after a
random delay period.
Communication distances vary depending on the type and thickness of
material around a wireless node. The transmitter power output, the type of
antenna used and the amount of attenuation through materials also affects the
useable range. Electromagnetic noise, reflections, the amount of network
traffic, other radio devices operating in the same frequency band also affect
range and overall performance. In an infrastructure network the number of
access points and their coverage pattern also affect how well the system
operates. Typically an 802.11 device operating indoors will have a range
from 100 feet minimum to about 500 feet maximum. Outdoors, some
products, using high gain antennae may achieve line-of-sight ranges of five
miles or more.
Security is a significant concern for WLAN users. Whether security threats
originate intentionally or unintentionally, wireless systems are more
susceptible than wired systems. ES1AWB serial servers offer several security
options including WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected
Access), PEAP (Protected EAP) w/EAP-MS-CHAPv2 and others.
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com